With respect to microwave foods, it is often desirable that the microwave heating be controlled in order to prevent overheating of the food. One example is microwave heating and popping of popcorn. If popped kernels are subjected to prolonged microwave heating, scorching occurs. Currently, microwave popcorn is packaged in flexible paper bags. Embedded in the popcorn bag is a susceptor used to absorb microwave energy and aid popcorn heating and popping. Typically in packaging microwave popcorn, a slurry including popcorn kernels are located on top of the susceptor, the bag is folded over itself to a compact size. When the bag is placed in the microwave oven, instructions typically call for at least partial unfolding of the bag and placing the bag on a microwave transparent shelf or floor of the oven with the susceptor below the popcorn. When the popcorn bag is heated in the microwave oven, steam or water vapor from the popping popcorn causes the bag to further unfold and inflate. With the current bag designs, popped kernels are unprotected from microwave irradiation after popping. When heated above about 210.degree. C., popped kernels begin to scorch. The present invention overcomes this shortcoming of prior art popcorn bags (and other microwave-related food packages) by providing a bag or package that initially exposes the popcorn (or other food load) to a controlled combination of both propagating and non-propagating (evanescent) microwave irradiation to pop the kernels or otherwise heat the food load and thereafter reduces the microwave irradiation to the bulk of the popped kernels (or other heated food load), to reduce the possibility of scorching (and other undesirable results of overheating) that would otherwise occur. When a popcorn load is referred to herein, it is to be understood that it generally refers to a load that includes a popcorn kernel hybrid engineered for desired agronomic and microwave popping properties and consistent with generally available major commercially available microwave popcorn offerings, together with a butter type slurry having major constituents of soybean oil, salt, colorings, flavorings and the like. These components combine (in a typical load) to a weight of approximately 100 grams with about 80% or more (by weight) being the popcorn kernels themselves.